A multimedia (e.g., audio, video or image) fingerprint is a content-based compact signature that summarizes a multimedia recording. Multimedia fingerprinting technologies have been widely investigated and are increasingly used for various applications since they allow the monitoring of multimedia objects independently of its format and without the need of metadata or watermark embedding. In an example of the applications, given a fingerprint derived from a multimedia recording (e.g., audio or video), a matching algorithm searches a database of fingerprints to find the best match.
Various fingerprint algorithms to derive multimedia fingerprints have been proposed. Multimedia fingerprints can be described as low-bit rate identifiers that uniquely identify even small segments of a multimedia recording such as an audio file, a video file or an image file. A recording or segment which a fingerprint is derived from is also called as a multimedia object hereafter.
Fingerprints based on different fingerprint algorithms differ in the degree of robustness to content modifications and sensitivity to content change. In general, fingerprints are designed in a way that increased fingerprint robustness leads to a decrease in content sensitivity and vice-versa. It is difficult to achieve high robustness and high sensitivity with one fingerprint algorithm.